In Exercises 5–20, assume that the two samples are independent simple random samples selected from
19. Is Old Faithful Not Quite So Faithful? Listed below are time intervals (min) between eruptions of the Old Faithful geyser. The “recent” times are within the past few years, and the “past” times are from 1995. Does it appear that the
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- A researcher conducts a hypothesis test using a sample of n=20 with M =34 and s^2=36 from an unknown population.What is the df value for the t statistic?arrow_forwardx 1 2 3 4 5 P(X=x) 0.21 0.197 0.2 0.173 0.22 use the information in Table 3 to determine the probability that,from a sample of 10 randomly selected adults, exactly 3 of them exceeds the required standard for practices towards COFLU-20. (ii) identifying a suitable probability distribution to be used to find the probability that exactly three (3) adults, out of 10, exceeds the required standard for practices towards COFLU-20.State the value(s) of the parameter(s) for this distribution.arrow_forwardA hypothesis test produces a t statistic of t = 2.30. If the researcher is using a two-tailed test with a = .05, how large does the sample have to be in order to reject the null hypothesis?arrow_forward
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- Find the standard deviation of a discrete random variable X which satisfies P(X=1)=0.1,P(X=-1)=0.6, P(X=2)=0.3.arrow_forwardThe closer the numerator of a t-test gets to zero, the more likely it is that there is no statistically significant difference between the two means we are testing. True Falsearrow_forwardIf Z is a discrete random variable with possible values of -1, 0, and 1, and the probability mass function is given by P(Z = -1) = 0.4, P(Z = 0) = 0.3, and P(Z = 1) = 0.3, what is the standard deviation of Z?arrow_forward
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